2006 Cadillac SRX

My engine light came on(flashing) and the owner's manual said it was an emissions problem (probably) and to run through a full tank of high grade fuel and check the gas tank cap. I did these two things and the engine light remained on, but was not flashing.

The engine light then went off. Shortly after that the light came one, and I was unable to accelerate when I pressed the gas pedal. Although it was running I had the car towed to the dealership. Because I had an old "oil change" sticker on my window, they asked about when I had my oil changed last. I told them the next one would be due soon (I've only had the car for 6 months!). He said I would need to provide records of my last oil changes in order for the car to be covered under the factory warranty. Otherwise I will be liable for the repair. However, when giving this report, he had yet to actually diagnose the problem, he said they would be tearing it apart soon, and I could need a new motor!

I told him I used synthetic oil, and that the car sends a message to me when the oil needs changing. His response was " if the light comes on it's too late"!

Not sure if I should just go get my car and send it to another dealership! My factory warranty expired in 10 days! Am I getting the run around?